ANSI

Arduino library with basic ANSI display codes for terminal applications.

Description

ANSI codes are special codes that are send to a terminal e.g. VT100 to add attributes to displayed characters. Typical examples are bold, blink or colour. ANSI codes are also known as escape codes. The set of codes is large, however not all terminal types do support all codes.

Sending these ANSI codes to a simple ASCII only terminal like the one in the Arduino IDE might result in garbage. So use with care.

Breaking change 0.2.0

The gotoXY(x, y) has changed as the X and Y coordinates were swapped.

The code has been updated to explicitly mention which is row and which is column.

• gotoXY(uint8_t column, uint8_t row)

Related

• https://en.wikipedia.org/wiki/ANSI_escape_code
• https://github.com/RobTillaart/LineFormatter

Terminals tested

Tests are done with

• TeraTerm 4.102 + 4.106 (VT100, VT202, VT525 mode)
• Putty 0.71

See supportMatrix.md (limited)

Other terminal program's exist so please let me know if yours is working too. If not, please open an issue.

Interface

#include "ansi.h"

Constructors

• ANSI(Stream * stream = &Serial) wrapper around Serial. Can be a software serial too.
• VT100(Stream * stream = &Serial) derived class (wrapper)

Stream interface

• int available() to check if chars are available on the stream.
• int read() read a byte from the stream.
• int peek() preview the byte in the stream without fetching.
• void flush()

Stream interface also includes print(), println(), write().

Character modi

Most of these are supported (more or less) in terminal apps.

• void normal() normal intensity.
• void bold() bold or high intensity.
• void low() low intensity.
• void underline() idem.
• void blink() idem.
• void blinkFast() idem.
• void reverse() idem.

Colour

• void foreground(uint8_t fgcolor)
• void background(uint8_t bgcolor)
• void color(uint8_t fgcolor, uint8_t bgcolor)

Three helpers to map to the nearest colour.

• uint8_t gray2color(uint8_t gray)

• uint8_t grey2color(uint8_t grey) idem

• uint8_t rgb2color(uint8_t r, uint8_t g, uint8_t b)

• https://en.wikipedia.org/wiki/ANSI_escape_code#3-bit_and_4-bit

Positioning

• void clearScreen() clears screen and sets cursor to 0,0.
• void clearLine(uint8_t clear = toEnd) toEnd = 0, toStart = 1, entireLine = 2,
• void home() set cursor to 0, 0
• void gotoXY(uint8_t column, uint8_t row) set cursor to position. Note X == row and Y == column. See #13.
• void cursorUp(uint8_t x) idem.
• void cursorDown(uint8_t x) idem.
• void cursorForward(uint8_t x) idem.
• void cursorBack(uint8_t x) idem.

Experimental

Look into ansi.h for experimental functions and notes.

Version 0.1.6 added a number of experimental function that need more testing. Some are working with TeraTerm, others are unclear of fail. The user can uncomment these and verify if these work with their terminal.

Experimental getScreenSize()

Added in 0.2.2 (From PR #16 refactored) use with care.

• bool readCursorPosition(uint16_t &w, uint16_t &h, uint32_t timeout = 100) returns true if width and height are reported. Be sure to test the return value!
• bool getScreenSize(uint16_t &w, uint16_t &h, uint32_t timeout = 100) returns true if width and height are reported. Be sure to test the return value!
• inline uint16_t screenWidth() used after successful call of getScreenSize();
• inline uint16_t screenHeight() used after successful call of getScreenSize();

Experimental deviceType()

The int deviceType() function needs more testing.

See - #9

Type	Description
-1	unknown
1	VT52
2	VT100
3	VT220
other	unknown

As always, constructive feedback is welcome.

Experimental (working TeraTerm)

These functions need more testing and might work on your favourite terminal. As always feedback is welcome.

COLUMNS

• void set132columns()
• void set80columns()

MOVE WINDOW

• void moveWindowDown()
• void moveWindowUp()

PRINTING

• void printScreen()
• void setPrintingMode(bool on)

RESET

• void reset() terminal to initial state

Experimental (NOT working TeraTerm)

• void setSmoothScroll()
• void setJumpScroll()
• void printLine()
• void invisible() to be used for password?
• void strikeThrough()
• void setRGBforeground(uint8_t r, uint8_t g, uint8_t b)
• void setRGBbackground(uint8_t r, uint8_t g, uint8_t b)

Performance

Since 0.1.5 there is some focus on performance. Using ansi.print() and ansi.println() for printing text and numbers is improved a bit since 0.1.4 by adding the private write(array, length).

Since 0.2.0 the (internal) print() statements are replaced by write(). Although it are small improvements these add up.

Future

Must

• improve documentation
  • elaborate interface
  • colour info

Should

• test experimental functions
• test more terminal programs (Linux mac)
• add examples
  • DOS emulator?
  • experimental section

Could

• investigate a class hierarchy?
  • base class vs more extended class? (footprint?)
• increase functionality
  • which codes are generic / useful ?
• investigate performance.
  • add line buffer in write(c) to improve throughput?
  • need for flush() with line buffer?
• move code from .h to .cpp
• more derived classes

Wont

• move static strings to PROGMEM? as defines? roughly ~20 bytes PROGMEM for 4 bytes RAM...

Support

If you appreciate my libraries, you can support the development and maintenance. Improve the quality of the libraries by providing issues and Pull Requests, or donate through PayPal or GitHub sponsors.

Thank you,